1. Field of the Invention
The present invention relates to a seat slide apparatus for a vehicle seat in which a seat main body can be moved in a longitudinal direction.
2. Description of the Related Art
In this kind of seat slide apparatus, a lock plate has a portion near a base portion axially attached to a side surface of an upper rail in a freely rotatable manner. Since the lock plate has a significantly great length to a free end in which a lock tooth is formed, the free end side of the lock plate tends to move apart from the side surface of the upper rail when a load acts on the upper rail. Accordingly, the upper rail moves in a direction of releasing from a lock groove of the lower rail, so that there has been a risk that a lock function of the seat slide apparatus decreases.
The prior art has attempted to prevent the free end side of the lock plate from swinging in a direction of moving apart from the side surface of the upper rail. As shown in FIG. 1, a rivet 3 with a flange 3b having a locking portion 3a for locking a lock spring 2 is loosely fitted to a long hole 1a formed on a side surface of the upper rail 1. Lock plate 4 is mounted to the rivet 3 by caulking, and the upper rail 1 is held between the lock plate 4 and the flange 3b of the rivet 3. The above construction is required other than the rotatably mounted pivot portion of the lock plate 4.
However, in the seat slide apparatus mentioned above, the rivet 3 has a complex configuration integrally formed with flange 3b. This not only increases cost, but also increases the number of assembling processes for the lock plate 4.